#19 Rattata

A Forest Pokémon, Rattata. It likes cheese, nuts, fruits, and berries. It also comes out into open fields to steal food from stupid travelers.
– Ash’s Pokedex

Rattata is the first pure Normal type in National dex order. It’s also the first 2-stage evolution chain in National dex order. It looks like a regular mouse or rat, except purple, though the shiny version looks more like a regular mouse.

In Gen II (and its remakes), there’s a Youngster Joey on Route 30 who has a Rattata. If you get his phone number, he likes to call you to tell you about how his Rattata is in the Top Percentage of Rattata. Even after his Rattata evolved into Raticate, he still brags about his Rattata.